The submarine had a maximum surface speed of 9.7 knots (18.0 km/h; 11.2 mph) and a submerged speed of 12.5 knots (23.2 km/h; 14.4 mph). When submerged, the boat could operate at 4 knots (7.4 km/h; 4.6 mph) for 194 nautical miles (359 km; 223 mi); when surfaced, she could travel 2,600 nautical miles (4,800 km; 3,000 mi) at 8 knots (15 km/h; 9.2 mph). U-2331 was fitted with two 53.3 cm (21 in) torpedo tubes in the bow. She could carry two preloaded torpedoes. The complement was 14–18 men.[1] This class of U-boat did not carry a deck gun.

Service history

Completed in September 1944, U-2331 was undergoing a fast-track working-up period in the Baltic under her commander Oberleutnant zur See Hans-Walter Pahl under the observation of Klaus Vernier, a highly experienced U-boat commander and tactical expert. On 10 October, just 28 days after her completion, U-2331 dived and failed to surface in the sea off the Hel Peninsula. Four of the reduced crew (including the captain), escaped the sinking ship but 15 did not, including Vernier.

The Kriegsmarine conducted an investigation into the loss, at which it was revealed that either the captain or Vernier had ordered the submarine to submerge whilst travelling in reverse, thus unbalancing the boat and causing it to sink uncontrollably. A handful of men on the conning tower survived as the boat sank under them. The wreck was raised and taken to Gotenhafen (Gdynia, Poland), but the time submerged underwater had irreparably damaged the boat's systems, and the remains were scrapped.